No sound from speaker, but works with external speaker plugged in
The oddest thing - my amp just cut out one day when I was playing - checked all the cables, etc. One of my bandmates got the bright idea to plug in a floor monitor to the external speaker jack, and then the amp was putting out sound, as well as the monitor. When we unplugged the external speaker, the amp went back to not working. Any ideas on what might be going on here? This is a solid-state CRATE GT212.
- If you need clarification, ask it in the comment box above.
- Better answers use proper spelling and grammar.
- Provide details, support with references or personal experience.
Tell us some more! Your answer needs to include more details to help people.You can't post answers that contain an email address.Please enter a valid email address.The email address entered is already associated to an account.Login to postPlease use English characters only.
Tip: The max point reward for answering a question is 15.
If you are competent with electronics, open it up and check the fuse(s). Especially if no lights come on. If you get voltage, then check the jacks you plugged into- they may have dirty interrupt contacts. When you plug the jack in- it opens those contacts that otherwise are closed making the circuit to the cabinet's built in speaker. Contact cleaner should clean them up if that is the issue.
While it is possible there is a power supply issue, you can see that quick with a voltmeter, it is not likely you did much more than blow a fuse.- very possible if you unplugged speakers with the amp operating..
If you think you killed it- you usually still get distorted noise.
Try using your guitar cord to plug in and out of the headphone jack several times while unit is on. There is a circuit that disconnects the speaker when using headphones and the circuit is activated when something is plugged into the headphone jack. This "switch" can get dirty and cause the can get dirty and cause the problem you describe.
Something has probably failed or become a bad joint. If you turn up the gains and volume to max is there any hiss or hum from the speaker? If not there will be a problem in the power amp or power supply. Check fuses at back. The speaker may be open circuit too, that is easy to check with a multimeter. If you can't get far yourself, you'll need a repairman.
Solid state amps are not that reliable these days, there are so many things that can fail due to all the effects that people demand to be built in. Look at how many people are reporting problems with ss amps here.
If the speakers are cut off when externaal cables are connected to line outs, possibly the jack sensing switch for the right channel thinks that a plug is in there... you might cycle one in and out to see if that might fix.
Another thing is they LIKELY have a PAN control setting and it might be set full left. The external MP3 would NOT be under PAN control, only the keyboard voices would be affected by it.
Please note that I do not have the schematic for this unit. One possibility is they have "foldback" protection to pprotect the power amps from excessive load. If you drive such a system hard, it will shutdown and stay down till you recycle the power.
Try this: Bring your gain up SLOWLY and see if the unit immediately cuts off at less gain than you have been trying.
If you reach a "trigger point", the unit probably is going into protection mode.
Sometimes people get junky speakers like car speakers and they are so inefficient compared to good music speakers that they overload these amps trying to drive them. You should be using name brand speakers like Peavey, Yamaha, etc.
Also I would like you to check your guitar on another system to make sure it doesn't cut out. MANY guitars have a battery amp in them and if the circuitry is bad or the battery weak, as soon as they are played hard, the battery collapses and the sound diminishes.
Do these tests I have suggested and see what you find out. I am an electrical engineer with lots of troubleshooting experience... If I could only reach out with my test equipment and measure a few things...
Try disconnecting the speaker from the amp with the amp unplugged from your power. Never work on an amp when its plugged in unless you know how dangerous it is. Check for resistance across the speaker terminals with a volt ohm meter to see if you have a blown speaker. Thats the first thing to look for. You should here a hiss or a low hum when your amp is on and you plug a guitar cord into the input without the guitar. Check those two things first.